Dishwasher leak and flood codes: what to do right now

What the machine has detected

Every dishwasher code rated danger on this site has one meaning underneath the brand's wording: water is somewhere it should not be. In most cases that is the base tray — a shallow pan under the tub where a float switch sits, and where anything that escapes from a hose, a seal or the tub itself ends up. When the float lifts, the machine shuts off every electrical component except the drain pump and runs that pump continuously — AEG list the constant hum as a symptom of i30 in its own right. In a smaller number of cases the code means water is still coming in when the machine has told the valve to close.

The codes, so you can find yours: the anti-flood family is Bosch, Siemens and Neff E15 — shown on newer displays as E:31-00 or E:3100 — AEG, Zanussi and Electrolux i30, Miele F70, Hotpoint and Indesit F01, Beko E01, Samsung LC, LG AE, Candy and Hoover E4, CDA F1, Baumatic E4 or, on a Baumatic without a display, the intense wash and economy wash lights flashing together, and on a Lamona the internal leak light pattern. The fill-valve family is Bosch E16, Hotpoint F02, Candy E21 and CDA F3. Samsung HC, a high-temperature code, is the one danger code here that is not about water, and Samsung's instruction for it is the same as for a leak: isolate at the breaker.

The next two minutes

Tap first. The isolation valve on the inlet hose under the sink, or the stopcock if you cannot find it. The reason for the order is simple: water keeps arriving whether or not the machine has electricity, and on a fill-valve code the machine has already lost the thing that would normally stop it. CDA are the one manufacturer who put the plug before the tap, and their code page here argues it through; the practical answer is do both, quickly, and if you can only do one, the tap.

Then power. Switch off at the wall and, if you can reach it without standing in water, pull the plug. On an integrated machine the socket is often behind the adjacent cupboard's back panel. Do not reach for a socket while standing in the puddle, and do not use the machine's own buttons as the isolation — Samsung's manual sends you to the consumer unit for exactly this reason.

Then towels, and only then a look. Where the water is tells you something. A pool at the front, under the door, points at the seal or at foam. A pool at the back or side, or nothing visible at all with the machine humming, means the water is in the tray and the float has done its job.

The manufacturers' own sequences agree with that, and it is worth seeing how much they agree. Miele: close the stopcock, switch the dishwasher off, disconnect the mains plug, contact Service. Beko: cut off the electricity, close the valve, contact the authorised service agent. Lamona: turn off the water and the electric, and call. Samsung's manual: close the water valve, switch the breaker off at the consumer unit, contact the installer. Bosch and AEG: turn off the tap and call. The one manufacturer whose published instruction is out of step is LG, whose entire entry for AE is "Water leakage problem. Call for service if the same problem occurs again." That reads as an invitation to run it once more and find out. Do not take it.

What the hum means

The sound that sends people to the plug is a machine that will not respond to anything and hums steadily. On an anti-flood trip that hum is the drain pump running continuously, and AEG list it as a symptom of i30 rather than a fault in itself. Miele explain in their F70 article that the pump stops once you disconnect the power, so when you unplug the machine and the noise ceases, that is the protection having worked, not something else having failed. The machine is not getting worse while it hums. It is holding the line until you turn the tap off.

The advice to refuse

Search any of these codes and the top result will tell you to tip the machine backwards to about forty-five degrees, let the tray drain out of the back, and let the float drop so the code clears. It does clear the code. Three published things make it a poor idea.

Bosch's GB manual says to transport the appliance upright only, to prevent residual water running into the controls and damaging the appliance. Candy say that for the overflow safety device to work correctly the machine should not be moved or tilted during operation, and that if it must be tilted or moved the washing cycle should be complete and no water left inside. And the tray you are pouring water out of is the tray the heating element, the circulation pump and the float switch live in, under the tub, with their connections. Tipping sends whatever is in the tray across all of them. The code clears because the float drops; the leak that filled the tray is still there, and the next cycle fills it again, possibly with a wet heater connection this time.

The same applies to running it again to see. The reset guide explains why the manufacturers deliberately publish no reset for these codes; the reset guide has the detail.

What usually caused it

The causes are the same across brands because the machines are built the same way, and they run from cheap to serious.

• Foam. Washing-up liquid in the detergent compartment, or a rinse of it left on a pan, produces enough foam to climb over the tub and reach the tray with nothing broken. Samsung ask you to confirm only dishwasher detergent was used; Miele have a separate foam code, F52, but say severe cases can trip F70 instead. This is the one cause an owner can rule out for nothing — once the machine is isolated and the tray has been allowed to dry — and it is worth knowing before an engineer arrives.
• A hose or a clip. A perished internal hose or a slipped clip dripping into the tray. The commonest real cause and one of the cheaper repairs.
• The door seal. Gone hard at the lower corners, so water runs down the inside of the door and collects underneath rather than escaping at the front where you would notice. Samsung also point at debris on the seal and tall items in the racks distorting the door as it closes.
• A machine that is not level. Candy tie the overflow device's correct operation to the machine sitting properly; a machine that has settled holds water against one corner of the seal.
• The tub or sump. A split or a failed seal at the bottom of the machine. The serious end, and the reason no one can price a leak before finding it.
• A stuck float. The protection reporting water that has gone. Real, but a conclusion an engineer reaches after ruling out a leak, not a reason to reset and carry on.

On the fill-valve codes the list is shorter: the inlet valve is not closing, and the machine cannot fix that itself. Hotpoint's own action for F02 does not say to turn the tap off; the code page here does, and explains why.

The Hotpoint and Indesit safety notice

Hotpoint and Indesit dishwashers built between 2005 and 2015 are covered by a live safety notice. Hotpoint's wording is that a small number of dishwashers have an electrical component that can fail, which may lead to overheating and in rare cases a potential fire hazard, and their instruction for an affected machine is not to use it until after the repair visit. The safety-notices index goes further: unplug and refrain from using the appliance until it has been replaced or modified. The model checker is at hotpoint.co.uk/service/safety-notice-dishwasher, and it needs the model number from the rating plate, which on a dishwasher is on the top or side rim of the door, visible when the door is open — Bosch publish that position for theirs, and the Hotpoint safety notice asks for the number as printed there. A machine in that range that has just reported a leak code has two reasons to stay off, and the free modification is worth booking before, or instead of, a paid repair. Do not confuse it with the separate recall on Hotpoint and Indesit freestanding gas cookers, which is the banner you will meet first on their site.

What it costs, and who to call

The code pages put a hose, clip or seal repair at roughly £90 to £170 on most brands and £70 to £160 on a Candy or Beko, and sump or tub work at £150 to £280, because substantially more has to come apart. Miele sit above that, at £120 to £220 for a hose or seal and considerably more for the tub. On a Bosch whose AquaStop itself has failed and caused damage, Bosch's own guarantee may apply, and it is worth raising with them before paying anyone. If the cause was foam, the repair is a dry tray and a different detergent.

The person to call is a qualified appliance engineer. There is no statutory register for appliance repair in the UK, so the assurance is competence rather than a card; ask whether they have worked on your brand, and give them the code, the display generation if it is a Bosch-group machine, and where the water was. The dishwasher leaking symptom page covers what to tell them if the machine has not shown a code at all.

Sources

The isolation instructions are quoted from the manufacturers' own documents as recorded on each code page: Miele's F70 article, Beko's manual, the Howdens Lamona manual, Samsung UK's manual and support pages (which the LC page compares, because they disagree), the Bosch and AEG support articles, CDA's fault table and LG's owner's manual. The anti-flood mechanism and the hum are as AEG and Miele describe them. The "transport upright" instruction is from the Bosch GB dishwasher manual and the levelling warning from Candy's manual. The safety notice wording is from Hotpoint's dishwasher safety notice page and their safety-notices index. Cost brackets are the code pages' own.